The eight Atlantis and International Space Station crewmembers will start their day with a dry run of a spacewalk from the station's new Quest airlock, completing their testing and activation of the airlock. Atlantis spacewalkers Mike Gernhardt and Jim Reilly, assisted by Pilot Charlie Hobaugh and Expedition Two Flight Engineer Jim Voss, will simulate spacewalk preparations beginning around 7 p.m.

Atlantis Commander Steve Lindsey and Mission Specialist Janet Kavandi will assist with the final checks of the airlock later in the morning. Subsequently, all eight crewmembers will gather to review the procedures for Friday's spacewalk, the third of the mission. During that spacewalk, Gernhardt and Reilly will attach the final nitrogen gas tank to the airlock, assisted by Voss and Expedition Two Flight Engineer Susan Helms who will be operating the station's robotic arm. At 10:11 p.m., the two crews will participate in a joint news conference with media representatives at several NASA centers and the Russian Mission Control Center in Korolev. That conference will run for 26 minutes and will be shown live on NASA TV. In addition, Lindsey is scheduled to downlink a tour of the Quest airlock around 3 a.m.

Station Commander Yury Usachev will perform various periodic maintenance duties on the station's Russian systems, as well as help fellow crewmates Voss and Helms prepare for robotics operations related to Friday evening's spacewalk.

The Atlantis crew was awakened at 4:04 p.m. by the song "A Time To Dance" by Janet Giroux played by the Space Center Intermediate School Symphonic Band. The band was directed by Giroux and the song was played for Reilly.